Material storage and handling equipment

ABSTRACT

A storage apparatus having a stack of trays disposed one upon another within a framework, and pressure fluid units in the framework associated with the trays except the lowest tray, and being selectively extensible to lift a number of trays off the trays beneath enabling a portion of the stack to be moved out of the framework leaving the upper portion within the framework to permit access to the top tray of the moved out portion.

United States Patent Inventor Norman Welch Harrogate, England App]. No. 792,662

Filed Jan. 21, 1969 Patented Apr. 20, 1971 Assignee B. C. Barton 8: Son Limited Tividale, Warley, England MATERIAL STORAGE AND HANDLING EQUIPMENT 8 Claims, 7 Drawing Figs.

US. Cl 2111/15 Int. Cl A47l 3/08 21 1/1.5,

Field of Search [5 6] References Cited UNITED STATES PATENTS 1,062,556 5/1913 Smith 211/175 2,064,096 12/1936 211/151X 3,154,197 10/1964 211/162X 3,247,982 4/1966 211/151 3,465,897 9/1967 Schumann 211/151 Primary Examiner-Nile C. Byers, Jr. AttorneyMarshall & Yeasting ABS 1" CT: A storage apparatus having a stack of trays disposed one upon another within a framework, and pressure fluid units in the framework associated with the trays except the lowest tray, and being selectively extensible to lift a number of trays off the trays beneath enabling a portion of the stack to be moved out of the framework leaving the upper portion within the framework to permit access to the top tray of the moved out portion.

PMEWEDAPRZOIEIH 3575297,

SHEET 2 BF 4 I Fig. 2.

PATENTED APR 20 um SHEEY l 0F 4 MATEEMAL STGMGIE AND HANDLING EQUIPMENT This invention relates to material storage and handling apparatus of the kind comprising a stack of superposed frames, trays, platforms or the like each capable of storing a quantity of material, and these will be collectively known as trays for the purposes of this specification, and their precise nature will depend upon the type of material to be stored; the trays are located in a framework and engage each with the next therebelow. The apparatus includes means for spacing a lower portion of the stack from an upper portion of the stack so as to disengage the two portions one from another, and means for moving the lower portion out of the framework so as to expose the uppermost tray in the moved portion for access. The top tray in the complete stack may be accessible without movement out of the framework, or it may be necessary to move the complete stack out of the framework without any separation of the parts for this depending upon the particular design employed. Hence each tray is accessible by moving a lower portion including that tray and the trays therebelow out of the framework.

The object of the present invention is to provide improved apparatus of this kind.

in accordance with the present invention apparatus of the kind referred to is provided with at least one pressure fluid unit in the framework associated respectively with each of the trays except the lowest tray, said unit or units being selectively extensible to lift a number of trays so as to separate the stack into two parts and enable the lower part to be moved out of the framework leaving the upper part within the framework.

Whilst each tray may merely rest upon the tray next below, it is preferred to provide a positive detent and socket means to couple each tray to the next below and the pressure fluid units are then extensible for a sufficient distance to disengage these means. Conveniently, each detent is a cone or dome, one being provided at each engagement point, for example at each corner of each tray, the sockets having corresponding recesses in the next tray below. The cones or domes may be supported by screw-threaded members to enable the tray spacing to be varied, thus enabling each tray to be levelled during assembly of the apparatus and accommodate tolerances in manufacture.

Each tray may rest on abutment shoulders or flanges in the framework when the pressure fluid units are deenergized, that is contracted, and to be lifted from this abutment when the units are energized and extended. The pressure fluid units are preferably hydraulic capsules but may alternatively be jacks, that is small cylinders with extensible rams, and may be fixed to the framework and abut the trays. The capsules may be arranged vertically above one another in the framework. One capsule or the like may be located in the vicinity of each corner of each tray (above the lowermost tray) or where the trays are particularly long or likely to be particularly heavy when fully loaded, additional capsules or the like may be provided, for example spaced apart along each side of each tray, or duplicated at each point where a capsule or the like is provided.

In order that the invention may be more fully understood, an embodiment in accordance therewith will now be described, by way of example, with reference to the accompanying drawings in which:

lFllG. l is a side elevation of the apparatus of the invention,

H6. 2. is an end elevation of the same apparatus,

lFllGS. 3 and d are an enlarged view of the coupling means and lifling means, the lifting means being shown in FIG. 3 in its rest position and FlG. d in its raised position,

lFlG. 5 is a further side elevation showing the top three trays in their lifted positions,

H6. is is a view similar to FIG. d showing the bottom three trays partially withdrawn from the framework, and

PEG. 7 is a plan view of the bottom tray showing the means for moving the stack into and out of the framework.

Referring to FllGS. 1i and 2 of the drawings, the apparatus shown therein is adapted for storing and handling bulky and heavy articles which may be of several tons in weight and possibly several 10's of feet in length.

The apparatus comprises two-spaced pairs of main supports 1 built into a solid foundation 2, the main supports supporting a stack of substantially identical trays 3 arranged one above the other and nesting one within the other in the normal storage position of the apparatus. The bottom tray has wheels l arranged to run along a pair of rails 5 set into the solid foundation to form a track.

The upper portions of the sides of each tray are inset to form horizontal flanges 6 which act as supports for the trays above. Each tray except the bottom one has a pair of depending U-shaped members 7 arranged so that one am 8 of each U is attached to the bottom of the tray for example as by welding and the other arm 9 of the U forms a supporting surface which rests upon a respective flange 6 on the tray below. Thus by interengagement of the flanges and U-shaped members, the trays can nest one on top of the other to form a neat and compact assembly. The top arm of each U-shaped member also carries an abutment or jacking pad extending parallel thereto within the U for engagement with hydraulic lifting means to be described.

The main supports l have L-shaped brackets llll secured at intervals along their inner faces and to the base 12 of each bracket is secured a hydraulic lifting device shown as a jack or capsule 13. Each bracket base 112 extends substantially horizontally between the arms of one of the U-shaped members so that the jack fixed to the base lies beneath the aforesaid abutment on the top arm of the U.

Referring now to FlGS. 3,and 4, it will be seen that the lower arm 9 of each U-shaped member 7 carries a domeshaped detent lid and the flange 6 of each tray for supporting the tray above it has a corresponding socket 15. The detents are engaged in the sockets to locate the trays when the latter are in their normal storage positions. Each detent 14 is secured by screw and nut means to its respective arm 9 so as to be adjustable outwardly or inwardly of said arm within limits.

Referring now to FIG. 7, this shows a propulsion or traversing device for withdrawing the bottom tray, together with any other trays not lifted from the stack, out of the framework along the rails 5 to provide access to the top tray withdrawn. The device comprises a double acting hydraulic ram having a cylinder i7 fixed to the ground and a piston rod 1%, one end of the piston rod being connected to a pulley block 19, and the other end of the piston rod being attached to a further pulley block 20. A connecting member such as a rope, wire or chain 21 is passed around the pulleys on the blocks 119, 20 and around corresponding pulleys on further blocks 22, 23 fixed to the ground at either end of the stack,

and is anchored at one point to the lowermost tray as indicated in FIG. 7. There is thus formed a pulley system providing in known manner a mechanical advantage (of 4 in the case shown) so that movement of the piston rod by a given distance causes the tray to move four times this distance, and a cylinder can thus be used which is short relative to the stack movement provided.

Any number of pulleys may be used to give the desired mechanical advantage.

Mlicroswitches may be provided, in the case shown to cause the hydraulic supply to the ram to be cut off when the tray is withdrawn to its maximum extent.

Moreover, positive stops 2d provided on the trays are arranged to contact one or more of the main supports i when the trays are retracted to positions in which the detents and sockets are in alignment and these stops may incorporate switches arranged to initiate lowering of the raised trays into their storage positions. However, switches for these and other purposes maybe located in positions other than those described.

FllGS. 3 and ti show the two phases of operation of the apparatus required for gaining access to a tray, in this case the third tray from the bottom. It will be seen in FIG. 5 that the three uppermost sets of capsules 113 are extended by an amount sufficient to disengage the detents on the bottom tray of the raised group from the sockets in the tray below, thus leaving the three bottom trays free for movement along the track. The ram is then operated by causing hydraulic fluid to be applied thereto through suitable connections (not shown) and the bottom stack of three trays moves outwardly of the remainder to the position shown in FIG. 6 or further if desired to provide the required degree of access to the top tray.

All of the capsules are arranged to be connected alternately to a source of pressure fluid and to exhaust, and where hydraulic fluid is used as in the present case the source may be a pressure accumulator and/or pump connected to a reservoir. All of the capsules on each level, that is the complete group arranged to lift one particular tray, are connected through a common valve having alternate positions in which connection to pressure and exhaust respectively is made.

The valves may be arranged to be operated in any convenient manner. In the embodiment described, the valves may most conveniently be solenoid operated and connected in electric circuits to pushbutton switches for example so that selection of any particular switch energizes one or more solenoids so as to energize one or more groups of capsules and thus only one switch need be operated to energize all of the desired capsules to lift the desired number of trays. The buttons may conveniently be grouped on a panel and marked to indicate the respective effects which they produce. It is possible to raise a part of the stack by operating only those capsules acting on the lowermost tray of the stack part to be raised. It is preferred in general however to lift each tray that needs to be lifted by the use of its own capsules and all the capsules in the raised stack part are actuated.

When loading or unloading of the top withdrawn tray is completed, the trays are returned to the stack by pressing another button which is connected to hydraulic supply means to retract the ram cylinder which drives the withdrawn trays back into the stack. When this is completed the capsules are returned to their original positions either by pressing a further button or by arranging for automatic actuation thereof when the trays are fully retracted. Thus the rest of the trays are lowered back onto the top of the retracted trays and are located by engagement of the detents on the lowermost of the raised trays engaging in sockets on the uppermost retracted tray.

Numerous modifications may be made to the embodiment described. Thus, the lifting and lowering mechanism and/or traversing mechanism may be actuated pneumatically instead of hydraulically, although the latter is preferred since higher operating pressure and consequently smaller sized units can be employed. Moreover, more positive movement and height location can be obtained with hydraulic fluid due to its incompressibility. Mechanically operated linkages may alternatively be used to select the capsules to be raised. Any convenient mechanism may be used for moving the trays into and out of the framework. Thus instead of the ram described, a motorized rack and pinion gear arrangement, screw or chain device or rope gear may be employed for return of the trays into the framework. Where solenoid valves are employed an end of travel switch may deenergize all of the solenoids and return the operating buttons or switches to their initial positions. p

In the case of power failure or failure, or damage, of the hydraulic circuit, nothing happens when-the stack of trays are in the retracted storage position. All that can happen when a partial stack of trays are moved out to the load, or unload, position is that the pressure falls in the hydraulic load capsules and the capsules lower the trays to the bottom position of the capsule ram stroke, at which position they are securely supported until the power is restored, when the tray lift button, or switch, is reset and the valves energized, so lifting the trays up to allow the rest of the stack to be operated to the in or out position.

lclaim:

1. Material storage and handling apparatus comprising a framework, a stack of superposed trays disposed within the framework, each tray other than the lowermost tray being supported by the tray below and having associated therewith at least one pressure fluid unit which is mounted on the framework and is selectively extensible to lift the tray, whereby the part of the stack above a desired tray may be lifted and held in the framework to permit the remainder of the stack, with the desired tray on top, to be moved out of the framework.

2. Apparatus according to claim 1 wherein at least one positive detent means is provided on all but one of the trays, projecting toward an adjacent tray, such adjacent tray having a socket means arranged to receive such detent means, whereby all the trays are coupled together, the pressure fluid units being extensible to lift each tray to a sufficient height to uncouple it from the tray below by disengaging the coupling detent and socket means.

3. Apparatus according to claim 2 wherein each detent means is generally cone-shaped and is secured by a'screwthreaded member, such a detent means being provided at each comer of all but one of the trays, and the socket means consisting of corresponding recesses provided at each corner of all but one of the trays.

4. Apparatus according to claim 1 wherein the pressure fluid units are hydraulic jacks.

5. Apparatus according to claim 4 wherein a hydraulic jack is disposed adjacent each comer of each tray other than the lowermost tray.

6. Apparatus according to claim 1 wherein each tray other than the lowermost tray in the stack is provided with depending channels extending along two opposite sides of the tray, the upper flanges of the channels being secured to the bottom of the tray and carrying jacking pads against which the pressure fluid units act to lift the tray, and the lower flanges of the channels being normally supported by flanges formed on the sides of the tray below.

7. Apparatus according to claim 6 wherein the pressure fluid units are mounted by means of brackets on the framework and are disposed between the flanges of each channel to act upon the jacking pads.

8. Apparatus according to claim 1 comprising a pulley system for effecting withdrawal of the lower part of the stack of trays after the upper part has been lifted, and a hydraulic ram operatively connected to the pulley system. 

1. Material storage and handling apparatus comprising a framework, a stack of superposed trays disposed within the framework, each tray other than the lowermost tray being supported by the tray below and having associated therewith at least one pressure fluid unit which is mounted on the framework and is selectively extensible to lift the tray, whereby the part of the stack above a desired tray may be lifted and held in the framework to permit the remainder of the stack, with the desired tray on top, to be moved out of the framework.
 2. Apparatus according to claim 1 wherein at least one positive detent means is provided on all but one of the trays, projecting toward an adjacent tray, such adjacent tray having a socket means arranged to receive such detent means, whereby all the trays are coupled together, the pressure fluid units being extensible to lift each tray to a sufficient height to uncouple it from the tray below by disengaging the coupling detent and socket means.
 3. Apparatus according to claim 2 wherein each detent means is generally cone-shaped and is secured by a screw-threaded member, such a detent means being provided at each corner of all but one of the trays, and the socket means consisting of corresponding recesses provided at each corner of all but one of the trays.
 4. Apparatus according to claim 1 wherein the pressure fluid units are hydraulic jacks.
 5. Apparatus according to claim 4 wherein a hydraulic jack is disposed adjacent each corner of each tray other than the lowermost tray.
 6. Apparatus according to claim 1 wherein each tray other than the lowermost tray in the stack is provided with depending channels extending along two opposite sides of the tray, the upper flanges of the channels being secured to the bottom of the tray and carrying jacking pads against which the pressure fluid units act to lift the tray, and the lower flanges of the channels being normally supported by flanges formed on the sides of the tray below.
 7. Apparatus according to claim 6 wherein the pressure fluid units are mounted by means of brackets on the framework and are disposed between the flanges of each channel to act upon the jacking pads.
 8. Apparatus according to claim 1 comprising a pulley system for effecting withdrawal of the lower part of the stack of trays after the upper part has been lifted, and a hydraulic ram operatively connected to the pulley system. 